Field of the Invention
The present invention relates to a technique of processing a surface peripheral area of a semiconductor wafer, a glass substrate for a liquid crystal display, a glass substrate for a plasma display, a substrate for an optical disk, a substrate for a magnetic disk, a substrate for a magnetooptical disk, a glass substrate for a photomask, and a substrate for a solar cell, for example.
Description of the Background Art
Not many device patterns (circuit pattern) are formed to reach a place as near as an end face of a substrate. In many cases, a device pattern is formed on a surface region spaced inward a given width from an end face of a substrate.
However, in a film formation step performed to form a device pattern, a film may be formed to reach a place outside a region where the device pattern is to be formed (this region is hereinafter simply called a “device region”). The film formed outside the device region is not only being unnecessary but it might also become a cause for various troubles. As an example, the film formed outside the device region might come unstuck during a process step. This may bring about the danger for example of yield reduction or a trouble in a substrate processing apparatus.
This may be handled by the process of removing a thin film by etching formed outside a device region (what is called bevel etching process). An apparatus responsible for such process has been suggested (see Japanese Patent Application Laid-Open Nos. 2008-300454, 2011-066194, 2009-070946, 2006-210580, 2001-070861, and 2003-264168, for example).
If a surface peripheral area outside a device region is processed with a processing liquid, the processing liquid supplied to the surface peripheral area might go into the device region (more specifically, the processing liquid might bounce off the surface peripheral area into the device region). Entry of the processing liquid into the device region acts disadvantageously on a device pattern, bringing about the danger of yield reduction.